<template>
 <div class="wrapper">
  <swiper :options="swiperOption" v-if="showSwiper">  <!--swiper有完整的list数据来创建，而不是空数组，空数组的时候length是为0-->
    <swiper-slide v-for="item of list" :key="item.id">
        <img class="swiper-img" :src="item.imgUrl">
    </swiper-slide>     
    <div class="swiper-pagination"  slot="pagination"></div>
  </swiper>
 </div>
</template>
<script>
export default {
    name:'HomeSwiper',
    props: {
        list:Array
    },
    data () {
        return {
            swiperOption:{
                pagination: '.swiper-pagination',//加入轮播按钮
                loop:true, //循环轮播
                autoplay: 3000,//3秒切换一次
                
            }
        }
    },
    computed:{
        showSwiper () {
            return this.list.length
        }
    }
}
</script>
<style lang="stylus" scoped>
.wrapper >>>  .swiper-pagination-bullet-active //swiper样式穿透
    background:#fff !important
.wrapper
    overflow:hidden
    width:100%
    height:0
    padding-bottom:31.25% //它高度相对于它宽度自动撑开31.25% height:31.25vw
    background:#eee   
    .swiper-img
        width :100%
</style>